399831817682025 has 189 divisors, whose sum is σ = 754041092020479. Its totient is φ = 210218832195840.

The previous prime is 399831817681993. The next prime is 399831817682053. The reversal of 399831817682025 is 520286718138993.

The square root of 399831817682025 is 19995795.

It is a perfect power (a square), and thus also a powerful number.

399831817682025 is a `hidden beast` number, since 3 + 9 + 98 + 318 + 17 + 6 + 8 + 202 + 5 = 666.

It can be written as a sum of positive squares in 13 ways, for example, as 10512827037801 + 389318990644224 = 3242349^2 + 19731168^2 .

It is not a de Polignac number, because 399831817682025 - 2⁵ = 399831817681993 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 188 ways as a sum of consecutive naturals, for example, 197058558711 + ... + 197058560739.

Almost surely, 2^{399831817682025} is an apocalyptic number.

399831817682025 is the 19995795-th square number.

399831817682025 is the 9997898-th centered octagonal number.

It is an amenable number.

399831817682025 is a deficient number, since it is larger than the sum of its proper divisors (354209274338454).

399831817682025 is an frugal number, since it uses more digits than its factorization.

399831817682025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4232 (or 2110 counting only the distinct ones).

The product of its (nonzero) digits is 313528320, while the sum is 72.

The spelling of 399831817682025 in words is "three hundred ninety-nine trillion, eight hundred thirty-one billion, eight hundred seventeen million, six hundred eighty-two thousand, twenty-five".